1. Producing a display of lustrous, rainbowlike colors: an iridescent oil slick; iridescent plumage.
2. Brilliant, lustrous, or colorful in effect or appearance: "The prelude was as iridescent as a prism in a morning room" (Carson McCullers).

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.